Re: [HACKERS] "DML"

On Fri, 11 Jun 1999, Don Baccus wrote:

> At 04:28 PM 6/11/99 +0000, Thomas Lockhart wrote:
>
> >Would it be acceptable to replace "DML statement" with something like
> >"data-altering statement"? The phrase shows up in only two places in
> >our ~700 pages of docs and out of context it doesn't seem to add
> >value...
>
> It would probably be OK. DML seems to be one of those terms of
> art, not using it would seem odd to db geeks but they'd understand
> what you're saying. Using it is incomprehensible to the rest of
> us. So I'd vote for writing something non-experts can understand.

I dunno about that one Don. DML and its cousins (DDL and DCL) are
very much in common usage these days. DDL (Data Definintion Language)
would be CREATE TABLE and so on whilst DML is INSERT INTO, UPDATE
and DELETE FROM...DCL (Data Control Language) usually deals with
permissions (GRANT/REVOKE) and often gets lumped in with DDL.

If you have a look at any comprehensive text that tells neophytes
(like yers truly) how to get a handle on SQL the subsets are defined
and referred to by their acronyms (e.g., Groff and Weinberg, 'LAN
Times Guide to SQL' which I keep handy...)

I'm not sure why they originally split up SQL but I know this:
proprietary databases like PROGRESS that claim to `support'
SQL generally don't support *all* the subsets.

PROGRESS, for example, does not support DCL at all. One must use
the `data dictionary', an awkward user interface. It claims to
support DDL but you can't access the tables you make with DDL cmds
via the dictionary. However, DML is fairly well supported, for what
that's worth...

------- North Richmond Community Mental Health Center -------
Anyway, hope I haven't muddied the waters but I wanted to say that
even non-SQL databases use these terms...and almost all SQL textbooks
cover them in detail.

Cheers,
Tom

Thomas Good MIS Coordinator, Senior DBA
Vital Signs: tomg@ { admin | q8 } .nrnet.org
Phone: 718-354-5528
Fax: 718-354-5056

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